Physical size restrictions of portable media devices often force the size of the loudspeakers in such devices to be quite small. Small speaker drivers suffer from low output levels and generally cannot reproduce the entire audible frequency range. As amplitudes are increased, distortion is introduced and more battery power is consumed. The noisy environments in which these devices are typically used only contribute to the problem.
Existing solutions to combat the low levels emanating from these devices tend to involve the addition of hardware such as external speakers. These solutions work counter to the idea of portability by either increasing the bulk of a device that has been carefully designed to be small or by creating a greater number of gadgets to be carried around by consumers.